The present invention relates to an improved process and apparatus for the manufacture of threaded fasteners having a coating or patch applied to the threads. More particularly, this invention relates to a method and device for the manufacture of sample fasteners, where it is necessary to develop new products or produce small quantities of existing products as samples for potential customers.
Prior art patents disclose various methods and devices for applying locking patches or coatings of resilient resin. Generally, a rotatable table or endless belt conveyor is disposed to receive fasteners and transport them through a plurality of stations to effect application of the coating. Examples of such disclosures include U.S. Pat. Nos. 4,100,882 an 4,835,819 to Duffy et al.
In the past attempts have been made to develop machines that could produce individual or small quantities of sample product as well as providing high volume production equipment with increased processing speeds and increased versatility at reduced costs. The attempts, however, have resulted in machines that were makeshift, not compact, and difficult to regulate. Some of these problems, and the concepts of some aspects of the present invention, are disclosed in U.S. Pat. No. 4,835,819, which is incorporated herein by reference.